Personally, when I'm working through a problem, I'll usually force it into words (either out loud or to myself), but that's a conscious action rather than a subconscious response. I choose to speak those things, and it's me (not an amorphous voice) who speaks them.
But often after forcing the thoughts into words I'll hit upon an interesting thread, and my mind will leap ahead faster than spoken language can catch up. It's only when I hit a roadblock that I slow things down into language-speed.